Predictors of progression in long-term nonprogressors. Australian Long-Term Nonprogressor Study Group.
It is now apparent that a proportion of individuals (5-8%) remains clinically free of HIV-1 disease with normal levels of CD4+ lymphocytes (> or =500/microl) for more than 8 years following infection. However, the proportion of these individuals who ultimately progress to AIDS remains to be established. We determined the virological and immunological characteristics of a cohort of long-term nonprogressors in Australia and examined the role of these factors in predicting disease progression. Individuals with documented asymptomatic HIV-1 infection for at least 8 years with CD4+ lymphocyte counts >500 cells/microl were recruited from hospital clinics and general practices serving the eastern area of Australia. CD4+ lymphocyte count, rate of CD4+ lymphocyte change, CD8+ lymphocyte count, beta2-microglobulin, immune complex dissociated (ICD) HIV-1 p24 antigen, and plasma HIV-1 RNA were measured at baseline and multiple visits at 6-month intervals over an average period of 2 years. Up to November 1996, 67 study participants were recruited, of whom 72% had been infected with HIV-1 for at least 10 years. HIV-1 RNA correlated with beta2-microglobulin, ICD p24 antigen, and the ability to isolate virus in culture but not with levels of CD4+ or CD8+ lymphocytes. Serum beta2-microglobulin was a stronger predictor of CD4+ lymphocyte decline than HIV-1 RNA and the only factor significantly associated with CD4+ lymphocyte decline. These findings show that the serum concentration of beta2-microglobulin is a strong predictor of immunological progression in people with long-term asymptomatic HIV-1 infection and provides additional prognostic information to HIV-1 RNA in determining the risk of disease progression.
Ashton
L J
LJ
National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, Australia.
Carr
A
A
Cunningham
P H
PH
Roggensack
M
M
McLean
K
K
Law
M
M
Robertson
M
M
Cooper
D A
DA
Kaldor
J M
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D016655:HIV Core Protein p24 / Q000032:analysis; D015658:HIV Infections / Q000276:immunology / Q000503:physiopathology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012367:RNA, Viral; D013997:Time Factors; D001613:beta 2-Microglobulin / Q000032:analysis
D016655:HIV Core Protein p24; D012367:RNA, Viral; D001613:beta 2-Microglobulin